U.S. Pat. No. 5,384,330 (Dieter et al.) teaches pharmacologically active 1,2,4-triaminobenzene derivatives of the General Formula:                 and their properties as anti-epileptic, muscle relaxing, fever-reducing and peripheral analgesic agents.        
U.S. Pat. No. 5,565,483 (Hewawasam et al.) teaches compounds of the formulae: wherein: R is hydrogen, hydroxy or fluoro; R1, R2, R3 and R4 each are independently hydrogen, C1-4 alkyl, halogen, trifluoromethyl, phenyl, p-methylphenyl or p-trifluoromethylphenyl; or R1 and R2, R2 and R3 or R3 and R4 are joined together to form a benzo fused ring; R5 is hydrogen or C1-4 alkyl; and R6 is chlorine or trifluoromethyl; or a nontoxic pharmaceutically acceptable salt, solvate or hydrate thereof, which are potassium channel openers useful for treating ischemia, convulsions and asthma.
The article Modulation of KCNQ2/3 Potassium Channels by the Novel Anticonvulsant Retigabine, Main et al., Molecular Pharmacology, 58: pp. 253-262, 2000, describes the actions of retigabine (D23129; N-[2-amino-4-(4-fluorobenzylamino)-phenyl]carbamic acid ethyl ester) in modulating the KCNQ2/3 potassium channels in oocytes in a 3-fold manner, i.e. retigabine shifts the voltage dependence of channel activation to more hyperpolarized membrane potentials, increases the rate of channel activation and slows channel deactivation.
U.S. Pat. Nos. 5,849,789 and 5,852,053 (both to Rostock et al.) teaches the use of retigabine for the treatment of neurodegenerative disorders, including those associated with stroke.
U.S. Pat. No. 5,914,425 (Meisel et al.) teaches novel crystalline forms of retigabine.
U.S. Pat. No. 6,117,900 teaches the use of retigabine, also known as N-[2-amino-4-(4-fluorobenzylamino)-phenyl]carbamic acid ethyl ester, for the treatment of neuropathic pain.